The study predicts more extremely wet years in the future - with potentially grave consequences for more than one billion people's well-being, economy, food systems and agriculture.
Too much rainfall can harm plants
More rainfall is not necessarily a good thing for the farming sector in India and its neighboring countries. As co-author Julia Pongratz from LMU explains: "Crops need water especially in the initial growing period, but too much rainfall during other growing states can harm plants - including rice on which the majority of India's population is depending for sustenance. This makes the Indian economy and food system highly sensitive to volatile monsoon patterns."
A look into the past underlines that human behavior is behind the intensification of rainfall. Starting in the 1950s, human-made forcings have begun to overtake slow natural changes occurring over many millennia. At first, high sun-light blocking aerosol loadings led to subdued warming and thus a decline in rainfall, but since then, from 1980 onwards, greenhouse gas-induced warming has become the deciding driver for stronger and more erratic Monsoon seasons.
A threat to the well-being of the Indian subcontinent
"We see more and more that climate change is about unpredictable weather extremes and their serious consequences," comments group leader and co-author Anders Levermann from PIK and Columbia University, New York/USA on the findings of the study published in the journal Earth System Dynamics. "Because what is really on the line is the socio-economic well-being of the Indian subcontinent. A more chaotic monsoon season poses a threat to the agriculture and economy in the region and should be a wakeup call for policy makers to drastically cut greenhouse gas emissions worldwide."
Article: Anja Katzenberger, Jacob Schewe, Julia Pongratz, Anders Levermann: Robust increase of Indian monsoon rainfall and its variability under future warming in CMIP-6 models. Earth System Dynamics. DOI: 10.5194/esd-2020-80.